Mana Tithe

Counter target spell unless its controller pays {1}.

Creative Outburst

Creative Outburst deals 5 damage to any target. Look at the top five cards of your library. Put one of them into your hand and the rest on the bottom of your library in a random order.
{U/R}{U/R}, Discard Creative Outburst: Create a Treasure token.

Burrog Befuddler

Flash (You may cast this spell any time you could cast an instant.)
When this creature enters, target creature an opponent controls gets -1/-0 until end of turn.

Witherbloom Pledgemage

Magecraft — Whenever you cast or copy an instant or sorcery spell, you gain 1 life.

Cram Session

You gain 4 life.
Learn. (You may reveal a Lesson card you own from outside the game and put it into your hand, or discard a card to draw a card.)

Blood Age General

{T}: Attacking Spirits get +1/+0 until end of turn.

Treasure

{T}, Sacrifice this token: Add one mana of any color.

Spiteful Squad

Deathtouch
Spiteful Squad enters with two +1/+1 counters on it.
When Spiteful Squad dies, put its counters on target creature you control.

Crushing Disappointment

Each player loses 2 life. You draw two cards.

Twinscroll Shaman

Expanded Anatomy

Put two +1/+1 counters on target creature. It gains vigilance until end of turn.

Go Blank

Target player discards two cards. Then exile that player's graveyard.

Unwilling Ingredient

Menace (This creature can't be blocked except by two or more creatures.)
{2}{B}, Exile Unwilling Ingredient from your graveyard: You draw a card and you lose 1 life.

Dina, Soul Steeper

Whenever you gain life, each opponent loses 1 life.
{1}, Sacrifice another creature: Dina, Soul Steeper gets +X/+0 until end of turn, where X is the sacrificed creature's power.

Silverquill Pledgemage

Magecraft — Whenever you cast or copy an instant or sorcery spell, Silverquill Pledgemage gains your choice of flying or lifelink until end of turn.

Galazeth Prismari

Flying
When Galazeth Prismari enters, create a Treasure token.
Artifacts you control have "{T}: Add one mana of any color. Spend this mana only to cast an instant or sorcery spell."